Coupling device for the attachment of an airbag module to a vehicle steering wheel in an oscillatory manner

ABSTRACT

The invention relates to a coupling device ( 16 ) for mounting an airbag module ( 14 ) to be oscillating on a steering wheel structure ( 12 ) of a vehicle steering wheel ( 10 ), comprising a mounting member ( 18 ) which includes, relative to a steering wheel axis (A), an axial bottom side ( 20 ) which in the assembled state of the vehicle steering wheel ( 10 ) faces the steering wheel structure ( 12 ) as well as an opposite axial top side ( 22 ) which in the assembled state of the vehicle steering wheel ( 10 ) faces the airbag module ( 14 ), a contact face ( 24 ) for a damping element ( 26 ) provided on the axial bottom side ( 20 ) for oscillating coupling of the mounting member ( 18 ) to the steering wheel structure ( 12 ), and comprising a locking element ( 28 ) disposed on the top side ( 22 ) of the mounting member ( 18 ) for locking with the prefabricated airbag module ( 14 ), wherein the locking element ( 28 ) is configured so that the airbag module ( 14 ) can be coupled to the mounting member ( 18 ) by a locking connection substantially in an axially fixed manner or in an axially restrictedly movable manner.

RELATED APPLICATIONS

This application corresponds to PCT/EP2017/070144, filed Aug. 9, 2017,which claims the benefit of German Application No. 10 2016 124 530.5,filed Dec. 15, 2016, the subject matter of which are incorporated hereinby reference in their entirety.

BACKGROUND OF THE INVENTION

The invention relates to a coupling device for mounting an airbag moduleto be oscillating on a steering wheel structure of a vehicle steeringwheel as well as to a subassembly and to a vehicle steering wheelcomprising said coupling device.

In a plurality of vehicle steering wheels vibrations which the driverfeels uncomfortable with are occurring during idling or in particularspeed ranges of the vehicle. Said vibrations are due, inter alia, to therigid coupling of the steering wheel to the steering column.

It is known to employ so-called vibration dampers to avoid undesiredsteering wheel vibrations so as to adjust the natural frequency of theoverall system such that it is within an uncritical range. At present,for example the gas generator of an airbag module disposed within thesteering wheel is used as a counter-oscillating damper mass.

Since vibration damping improves with an increasing damper mass, in DE37 10 173 C2 already a vehicle steering is described in which the entireairbag module is advantageously used as a damper mass. By means of theshear stiffness of the vibration dampers used, the first naturalfrequency of the steering wheel/module system can be adjusted to be solow that it will be within a speed range of the vehicle in which highexciting amplitudes will not yet occur (for example at about 120 km/h).

In the case of oscillating airbag modules, the vibration dampers arecurrently also used to realize a horn function at the vehicle steeringwheel, with a horn contact being provided at the airbag module and arespective mating contact being provided at the steering wheelstructure. Such vehicle steering wheel is disclosed, for example, inU.S. Pat. No. 8,720,942 B2.

However, it has turned out that in steering wheels of this typeespecially on rough road tracks faulty activations of the vehicle hornwill occur or, as compared to steering wheels having no vibrationdamping, longer contacting distances or higher contacting forces arerequired to activate the vehicle horn. This entails clearances ofundesired large size at the vehicle steering wheel and impaired comfortwhen activating the vehicle horn.

SUMMARY OF THE INVENTION

It is the object of the invention to provide a vehicle steering wheel ofsimple constructional design including a vibration damper having anintegrated horn function which has an as short actuating path aspossible and an as low actuating force as possible while a highfunctional safety is given.

In accordance with the invention, this object is achieved by a couplingdevice for mounting a prefabricated airbag module so as to beoscillating on a steering wheel structure of a vehicle steering wheel,comprising a mounting member including, relative to a steering wheelaxis, an axial bottom side which in the assembled state of the vehiclesteering wheel faces the steering wheel structure and an opposite axialtop side which in the assembled state of the vehicle steering wheelfaces an airbag module, a contact face provided on the axial bottom sidefor a damping element for oscillating coupling of the mounting member tothe steering wheel structure, as well as a locking element disposed onthe top side of the mounting member for engaging in the airbag module,wherein the locking element is configured so that the airbag module canbe coupled to the mounting member by a locking connection substantiallyin an axially fixed manner or in an axially restrictedly movable manner.Hence, with respect to the mounting member of the coupling device, onthe side of the steering wheel structure a vibration damping takes place(especially transversely to the steering wheel axis), whereas on themodule side a horn function can be realized (in the direction of thesteering wheel axis). In this way, the horn function and the vibrationdamping function are separated from each other in a simple manner sothat vibration excitations of the steering column and of the steeringwheel structure tightly connected thereto (e.g. on rough road tracks)are initially damped between the steering wheel structure and themounting member and no longer have an immediate effect on themodule-side horn function. An oscillating coupling of the mountingmember to the steering wheel structure by the damping element is to beunderstood within the scope of the present application in such way thatthe damping element enables damped vibration between the mounting memberand the steering wheel structure at least transversely to the steeringwheel axis, preferably also in the direction of the steering wheel axis.The maximum amplitude of possible vibration in the direction of thesteering wheel axis is preferably smaller than an axial actuating pathfor activating a vehicle horn.

The mounting member of the coupling device preferably is a mountingplate that extends substantially perpendicularly to the steering wheelaxis and especially includes plural locking elements, the lockingelements being preferably formed integrally with the mounting plate.Further, the locking elements may be identically spaced from thesteering wheel axis and may be arranged to be evenly spread in thecircumferential direction. This results in simple and quick assembly ofthe coupling device as well as in stable support of the airbag module.Alternatively, it is also imaginable, as a matter of course, to provideplural separate mounting members each having a locking element formounting the airbag module in an oscillating manner on the steeringwheel structure.

A damping element may be associated with each locking element, with thelocking elements and the associated damping elements being arrangedaxially in series.

According to one embodiment of the coupling device, on the axial topside of the mounting member a horn contact or an actuating member foractivating a beep upon contact between the horn contact and a matingcontact disposed at the airbag module is arranged, wherein the lockingelement is configured so that the airbag module can be coupled to themounting member in an axially restrictedly movable manner by the lockingconnection. In other words, in this case the entire airbag module isaxially displaced for actuating the vehicle horn, wherein both the horncontact and the mating contact are formed on components of the vehiclesteering wheel that are supported so as to be oscillating.

According to another embodiment, the coupling device includes a dampingelement which is adjacent to the axial bottom side of the mountingmember in the area of the contact surface and couples the mountingmember to the steering wheel structure in an oscillating manner so thatthe mounting member and the steering wheel structure are movablerelative to each other at least transversely to the steering wheel axis,especially wherein the damping element is preassembled at the axialbottom side of the mounting member. The damping element comprises avibration-damping material as well as, optionally, stop elements and/ormounting sleeves abutting on the vibration-damping material.

In this embodiment, the damping element preferably extends through anopening of the mounting member.

Moreover, the damping element may comprise an annular vibration-dampingmaterial having a radial shoulder, with an edge of the mounting memberopening forming a contact face and acting on the radial shoulder of thevibration-damping material.

In particular, the radial shoulder is in the form of a groove in thevibration-damping material, with the edge of the mounting member openingat least in portions engaging in the groove. This enables the dampingelement to be axially positioned and fixed on the mounting member in aquick and simple manner.

Incidentally, the object stated in the beginning is achieved by asubassembly comprising a steering wheel structure, an afore-describedcoupling device and a screw for mounting the coupling device to thesteering wheel structure which extends through the annularvibration-damping material, the vibration-damping material beingadjacent with an axial end face at least in portions to a screw head ofthe screw and/or being adjacent with an opposite axial end face at leastin portions to the steering wheel structure. The limitation of theaccommodating space for the vibration-damping material by componentspresent anyway such as the mounting member, the screw head and/or thesteering wheel structure is especially advantageous, because in suchcase separate mounting sleeves and/or stop elements can be dispensedwith. Ideally the damping element then is formed exclusively by thevibration-damping material.

Further, the invention comprises a subassembly including a steeringwheel structure, an afore-described coupling device and a dampingelement for oscillating coupling of the mounting member to the steeringwheel structure, wherein the damping element is arranged on the axialbottom side of the mounting member and is preassembled together with themounting member on the steering wheel structure.

The invention also comprises a subassembly having a prefabricated airbagmodule and an afore-described coupling device, wherein the airbagmodule, especially a module bottom of the airbag module, includes amating contact axially abutting on the horn contact, and wherein theairbag module is supported so as to be axially movable relative to themounting member for activating a beep.

The invention further relates to a subassembly comprising aprefabricated airbag module as well as an afore-described couplingdevice, wherein the airbag module includes a (manually operable) modulecover including a horn contact as well as another module componentincluding a mating contact axially abutting on the horn contact, themodule cover being supported to be axially movable relative to thefurther module component for activating a beep. In other words, the hornfunction is realized in this case “inside” the airbag module, whereinalso in this configuration variant the horn contact and the matingcontact are formed on components of the vehicle steering wheel supportedso as to be oscillating.

Finally, the object stated in the beginning is also achieved by avehicle steering wheel of an automotive vehicle comprising a steeringwheel structure, a prefabricated airbag module, an afore-describedcoupling device and a damping element for oscillating coupling of themounting member to the steering wheel structure, wherein the vehiclesteering wheel includes a horn contact and a mating contact axiallyabutting on the horn contact, and wherein both the horn contact and themating contact are formed on components of the vehicle steering wheelthat are supported to be oscillating. In particular, the coupling deviceand the damping element constitute a damper unit being preassembled onthe steering wheel structure. In this way, the vehicle steering wheelcan be assembled with especially little effort. The prefabricated damperunit is first connected, especially screwed, to the steering wheelstructure, whereupon the equally prefabricated airbag module is axiallyfed until it locks with the damper unit and thus is secured to thesteering wheel structure.

In an especially simply designed embodiment of the vehicle steeringwheel, the airbag module is secured to the steering wheel structureexclusively by the locking connection to the coupling device.

As an alternative, it is also imaginable, however, that an additional(locking) connection is provided between the airbag module and thesteering wheel structure which during normal driving of the vehicleadmits a limited relative movement, to be sure, but upon activation ofthe airbag module ensures that the airbag module does not completelydetach from the steering wheel structure. Consequently, the airbagmodule in this embodiment is secured to the steering wheel structure bymeans of the coupling device, wherein moreover another connectionindependent of the coupling device is provided between the airbag moduleand the steering wheel structure. This is of advantage as theconnections to the coupling device in this case need not be designed forthe extreme loads occurring, for example, upon activation of the airbagmodule.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the invention will be evident fromthe following description of preferred embodiments with reference to thedrawings, in which:

FIG. 1 shows a perspective exploded view of a vehicle steering wheelaccording to the invention comprising a coupling device according to theinvention in accordance with one embodiment;

FIG. 2 shows a schematic detailed section across the steering wheelaccording to FIG. 1 in the area of a locking element of the couplingdevice;

FIG. 3 shows a perspective exploded view of a vehicle steering wheelaccording to the invention comprising a coupling device according to theinvention in accordance with another embodiment;

FIG. 4 shows a schematic detailed section across the steering wheelaccording to FIG. 3 in the area of a locking element of the couplingdevice;

FIG. 5 shows a perspective view of a subassembly according to theinvention for a vehicle steering wheel comprising a coupling deviceaccording to the invention in accordance with one embodiment;

FIG. 6 shows a perspective view of a subassembly according to theinvention for a vehicle steering wheel comprising a coupling deviceaccording to the invention in accordance with another embodiment;

FIG. 7 shows a perspective view of a subassembly according to theinvention for a vehicle steering wheel comprising a coupling deviceaccording to the invention in accordance with yet another embodiment;

FIG. 8 shows a perspective view of a subassembly according to theinvention for a vehicle steering wheel comprising a coupling deviceaccording to the invention in accordance with yet another embodiment;

FIG. 9 shows a detailed section across the subassembly according to FIG.8 in the area of a mounting member of the coupling device according tothe invention;

FIG. 10 shows a perspective bottom view of the coupling device accordingto the invention in accordance with FIG. 9 in the area of the mountingmember;

FIG. 11 shows a perspective bottom view of a damping element for thecoupling device according to the invention in accordance with FIG. 10;

FIG. 12 shows a perspective view of a vehicle steering wheel comprisinga coupling device according to the invention; and

FIG. 13 shows a sectional view of a vehicle steering wheel according tothe invention comprising a subassembly in accordance with FIG. 8 and anassembled airbag module.

DESCRIPTION

FIG. 1 illustrates a vehicle steering wheel 10 comprising a steeringwheel structure 12, a prefabricated airbag module 14 and a couplingdevice 16 for mounting the airbag module 14 on the steering wheelstructure 12 in an oscillating manner.

The coupling device 16 comprises a mounting member 18 including,relative to a steering wheel axis A, an axial bottom side 20 which inthe assembled state of the vehicle steering wheel 10 faces the steeringwheel structure 12 as well as an opposite axial top side 22 which in theassembled state of the vehicle steering wheel 10 faces the airbag module14. On the axial bottom side 20 of the mounting member 18 a contact face24 for a damping element 26 for oscillating coupling of the mountingmember 18 to the steering wheel structure 12 is provided, whereas on theaxial top side 22 at least one locking element 28 is arranged forlocking with the airbag module 14.

The locking element 28 is configured so that the airbag module 14 can becoupled to the mounting member 18 by a locking connection substantiallyin an axially fixed manner or an axially restrictedly movable manner.

According to FIG. 1 the mounting member 18 is a mounting plate extendingperpendicularly to the steering wheel axis A and including three lockingelements 28. The mounting member 18 in this case is a metal part formedintegrally with the locking elements 28, wherein the locking elements 28are identically spaced apart from the steering wheel axis A and arearranged to be evenly spread in the circumferential direction.Alternatively, also configuration variants in which the mounting member18 is made from robust plastic material are imaginable, however.

The coupling device 16 in the shown embodiment includes three dampingelements 26 each of which is adjacent to a contact face 24 on the axialbottom side 20 of the mounting plate.

According to FIG. 1, a damping element 26 is associated with eachlocking element 28, wherein the locking elements 28 and the associateddamping elements 26 are arranged axially in series.

FIG. 2 illustrates a detailed section across the vehicle steering wheel10 according to FIG. 1 in the area of a damping element 26 and theassociated locking element 28 thereof.

The damping element 26 in this case comprises a vibration-dampingmaterial 27, for example an elastomer, as well as two stop elements 30and a mounting sleeve 32, each abutting on the vibration-dampingmaterial 27. The stop elements 30 are arranged axially on both sides ofthe vibration-damping material 27, while the mounting sleeve 32 extendsaxially between the stop elements 30.

The steering wheel structure 12 generally comprises a steering wheelarmature having a steering wheel rim, at least one spoke as well as ahub 34 and a hub plate 36. Moreover, the steering wheel structure 12usually further comprises a foam coating 38, for example made frompolyurethane, which at least partially surrounds the steering wheelarmature.

According to FIG. 2, the damping element 26 is secured to the steeringwheel armature via the mounting sleeve 32, with the mounting sleeve 32and the hub plate 36 forming a bayonet joint, for example.

It is further evident that the mounting member 18 including theintegrally formed locking element 28 is connected to the damping element26 by a screw 40 and to the steering wheel armature via the dampingelement 26 in this case.

The vibration-damping material 27 may be connected already in advance,e.g. by vulcanizing, to the mounting sleeve 32 and the stop elements 30so as to constitute the prefabricated damping element 26 with thelatter. Then the mounting sleeve 32 of each individual damping element26 is secured to the steering wheel structure 12, concretely to the hubplate 36 of the steering wheel structure 12, in the way of a bayonetlock. Finally, the mounting member 18 including its integrally formedlocking elements 28 is inserted and connected to the individual dampingelements 26 by the screws 40.

As will be exemplified later by way of FIG. 4, as a matter of coursealso alternatives for securing the coupling device 16 to the steeringwheel structure 12 are imaginable, however.

At any rate, in this way a subassembly comprising the steering wheelstructure 12, the afore-described coupling device 16 and at least onedamping element 26 for oscillating coupling of the mounting member 18 tothe steering wheel structure 12 is resulting, with the at least onedamping element 26 being arranged on the axial bottom side 20 of themounting member 18 and being preassembled together with the mountingmember 18 on the steering wheel structure 12.

According to FIGS. 1 and 2, the locking elements 28 of the couplingdevice 16 are rigid detent hooks which upon axially attaching theprefabricated airbag module 14 immerse in module bushes 42 and lock witha spring wire 43 mounted on the airbag module 14.

FIG. 3 illustrates a vehicle steering wheel 10 which differs from thesteering wheel design of FIG. 1 merely by a different configuration ofthe coupling device 16. In order to avoid repetitions, therefore theforegoing description is generally referred to and, in the following,mainly differences shall be discussed.

As compared to the embodiment according to FIG. 1, the coupling device16 according to FIG. 3 includes a different mounting on the steeringwheel structure 12 which is especially advantageous as regards theassembling effort. Instead of the stop elements 30 and the mountingsleeves 32, the coupling device 16 includes a base plate 44 forassembling the mounting member 18 on the steering wheel structure 12.

The vibration-damping material 27 in this case forms the damping element26 and can be connected, for example by vulcanizing, already in advanceto the mounting member 18 and the base plate 44 so that the dampingelement 26 is part of the prefabricated coupling device 16.

By way of the detailed section according to FIG. 4, it becomes evidentthat the base plate 44 of the coupling device 16 then only has to besecured to the steering wheel structure 12, wherein the base plate 44 inthe present embodiment is concretely screwed to the hub plate 36 of thesteering wheel structure 12 by a screw 46.

For further reducing the assembling effort for the coupling device 16,alternatively or additionally to screwing it is also imaginable to foamthe base plate 44 at least on the edge side into the foam coating 38 andthus to secure it to the steering wheel structure 12.

In order to prevent the airbag module 14 when being activated fromcompletely detaching from the steering wheel structure 12, directly onthe steering wheel structure 12 catch elements may be provided whichduring normal driving are spaced apart from the airbag module 14 andonly when the module is activated act immediately on the airbag module14 and withhold the module 14. Said catch elements are, for example,catch hooks or stop hooks 80 integrally formed on the steering wheelarmature of the steering wheel structure 12 (cf. FIG. 12).

According to a specific variant of the vehicle steering wheel 10 suchcatch elements are not provided. The airbag module 14 in that case issecured to the steering wheel structure 12 exclusively via the couplingdevice 16. In order to fix the locking element 28 of the coupling device16 especially tightly and reliably on the steering wheel structure 12 inthis case, a screw 48 indicated in broken lines in FIG. 4 is providedalternatively or additionally to the screw 46.

As regards a horn function of the steering wheel 10, it is especiallyadvantageous when the vehicle steering wheel 10 includes a horn contact50 as well as a mating contact 52 axially abutting on the horn contact50, wherein both the horn contact 50 and the mating contact 52 areformed at components of the vehicle steering wheel 10 that are supportedto be oscillating.

Components supported to be oscillating in this context are, for example,the mounting member 18 of the coupling device 16 as well as the airbagmodule 14 including all of its module components.

In FIGS. 5 to 7 various options for realizing such horn function on thevehicle steering wheel 10 are exemplified.

FIG. 5 illustrates a subassembly for the vehicle steering wheel 10comprising a prefabricated airbag module 14 and a coupling device 16which has a horn contact 50 for activating a beep on the top side 22 ofthe mounting member 18.

The airbag module 14 includes a mating contact 52 axially abutting onthe horn contact 50, wherein the (entire) airbag module 14 is supportedto be axially movable relative to the mounting member 18 for activatingthe beep. In other words, the prefabricated airbag module 14 hence iscoupled to the mounting member 18 to be axially restrictedly movable inthe assembled state of the vehicle steering wheel 10 via the lockingconnection to the locking elements 28 of the coupling device 16.

FIG. 6 illustrates another subassembly for the vehicle steering wheel 10which differs from the embodiment according to FIG. 5 merely by the factthat the airbag module 14 includes both the horn contact 50 and themating contact 52 axially spaced apart from the horn contact 50. Themounting member 18 supported to be oscillating includes at least oneaxially projecting actuating element 53 being axially abutting on thehorn contact 50, wherein two hook-shaped projections are provided asactuating elements 53 in the shown variant. For activating the horn, the(entire) airbag module 14 then is moved axially in the direction of themounting member 18 against a spring force, with the horn contact 50being deformed or displaced in the direction of the mating contact 52 bythe at least one actuating element 53 until the desired beep sounds whenthe contacts will touch each other.

Finally, FIG. 7 shows another embodiment of the subassembly for thevehicle steering wheel 10 comprising a prefabricated airbag module 14and a coupling device 16, with the horn function being integrated in theairbag module 14. The prefabricated airbag module 14 in this caseincludes a module cover 54 having the horn contact 50 and another modulecomponent 56 having the mating contact 52 axially abutting on the horncontact 50, wherein the module cover 54 is supported to be axiallymovable relative to the further module component 56 for activating thebeep.

As compared to the configuration variants according to FIGS. 5 and 6,hence a horn activation according to FIG. 7 is not effectuated bydisplacing the entire airbag module 14 but by a relative movementbetween the module cover 54 and the further module component 56, forexample a module casing.

However, all configuration variants share the fact that all componentsrequired for horn activation such as horn contacts 50, mating contacts52 and/or actuating elements 53 are supported to be oscillating on thesteering wheel structure 12. In other words, in a vehicle steering wheel10 including a vibration damper all of the components required foractivating the horn are part of the damper mass of the steering wheelvibration damper.

This is also applicable to the further embodiment of the coupling device16 shown in FIGS. 8 to 13 in which the damping element 26 extendsthrough an opening 58 of the mounting member 18.

In the present embodiment, the damping element 26 is made from thevibration-damping material 27 that is annular and has a radial shoulderon the outside. The mounting member opening 58 has an opening edgeincluding radially inwardly protruding projections 60, 62 which form thecontact face 24 for the damping element 26 and act on the radialshoulder of the vibration-damping material 27.

The radial shoulder in the vibration-damping material 27 is a peripheralgroove 64 according to FIG. 11, with the opening edge, concretely theprojections 60 of the opening edge engaging in the groove 64. In thisway, the elastic ring made from vibration-damping material 27 can bequickly and easily attached to the opening 58 so that the dampingelement 26 is axially positioned and fixed on the mounting member 18with minimum effort. Each projection 60 of the mounting member 18includes an axial bottom side 20 facing the steering wheel structure 12and forms a contact face 24 for the damping element 26 which in thepresent case corresponds to the annular vibration-damping material 27.

FIGS. 8 and 9 illustrate a subassembly comprising a steering wheelstructure 12, a coupling device 16 and a screw 66 for assembling thecoupling device 16 on the steering wheel structure 12, with the screw 66extending through the annular vibration-damping material 27.

With respect to a screw axis S the screw 66 extends from a screw head 68in the axial direction via a screw shank 70 to a free shank end 72. Thescrew shank 70 is stepped having a spacer portion 74 abutting on thescrew head 68 and a thread portion 76 abutting on the spacer portion 74toward the free shank end 72, which thread portion is separated from thespacer portion 74 by a step 78. The thread portion 76 has a smallershank diameter than the spacer portion 74 and is screwed into the hubplate 36 of the steering wheel structure 12 until the step 78 contactsthe hub plate 36 and prevents further screwing.

The locking element 28 extends in the axial direction from the mountingmember 18 to a free end and is substantially hollow-cylindrical, with alocking projection being integrally formed at the free end. An outerdiameter of the screw head 68 is somewhat smaller than an inner diameterof the locking element 28 so that the screw 66 can be inserted into thelocking element 28 and extends through the opening 58 of the mountingmember 18 into the hub plate 36. Said screwing of the mounting member 18in the area of the locking element 28 contributes to an especiallycompact design of the coupling device 16.

According to FIG. 9, an axial dimension of the spacer portion 74 of thescrew 66 is somewhat larger than an axial dimension of the mountingmember 18 in the area of the damping element 26 so that a predeterminedmovement of the mounting member 18 relative to the steering wheelstructure 12 is possible for vibration damping.

An axial dimension of the damping element 26 is at least as large as theaxial dimension of the distance portion 74 so that the vibration-dampingmaterial 27 is axially positioned as well as preferably slightlycompressed when the screw 66 is tightened.

The groove 64 in the vibration-damping material 27 is disposed so thatin a non-excited idle position of the vehicle steering wheel 10, themounting member 18 is held to be axially spaced apart from the screwhead 68 and the hub plate 36, especially substantially axially centrallybetween the screw head 68 and the hub plate 36, via its projections 60engaging in the groove 64.

Just as the projections 60, also the projections 62 of the mountingmember 18 axially abutting on the screw head 68 have axial bottom sides20 facing the steering wheel structure 12 each of which forms a contactface 24 for the damping element 26. Primarily the projections 60 serveas stops of the mounting member 18 on the screw head 68, however, so asto define a maximum relative movement between the mounting member 18 andthe steering wheel structure 12.

The vibration-damping material 27 is adjacent with an axial end face atleast in portions to the screw head 68 of the screw 66 and is adjacentwith an opposite axial end face at least in portions to the steeringwheel structure 12.

Thus, an accommodating space for the vibration-damping material 27 isdefined in the axial direction by the screw head 68 and the steeringwheel structure 12 as well as in the radial direction by the spacerportion 74 of the screw shank 70 and the mounting member 18. Therefore,separate stop elements 30 and mounting sleeves 32 (as shown in FIG. 2,for example) can advantageously be dispensed with.

If exceptionally high forces, as they occur e.g. upon activation of theairbag module 14, cannot be transmitted by the connection between theairbag module 14 and the coupling device 16 and/or by the connectionbetween the coupling device 16 and the steering wheel structure 12, itis imaginable that the airbag module 14 is not only secured to thesteering wheel structure 12 by means of the coupling device 16 but thatmoreover a further connection between the airbag module 14 and thesteering wheel structure 12 independent of the coupling device 16 isprovided.

This is illustrated, for example, in a vehicle steering wheel 10according to FIG. 12. In the shown steering wheel design, a couplingdevice 16 and a steering wheel structure 12 are provided, wherein amounting member 18 of the coupling device 16 in the form of a mountingplate is connected to the steering wheel structure 12 in an oscillatingmanner and includes locking elements 28 for locking with the airbagmodule 14. Furthermore, at the steering wheel structure 12 there areprovided catch elements which during normal driving are spaced apartfrom the airbag module 14 and only upon activation of the module actimmediately on the airbag module 14 and withhold the same. According toFIG. 12, said catch elements are detent hooks 80 integrally formed onthe steering wheel armature of the steering wheel structure 12.

FIG. 13 illustrates the vehicle steering wheel 10 according to FIG. 12with a coupling device 16 according to FIG. 9 and an assembled airbagmodule 14. Herefrom it is evident that the spring wire 43 tightlyconnected to the airbag module 14 engages both in the locking elements28 of the coupling device 16 and in the detent hooks 80 of the steeringwheel structure 12.

The invention claimed is:
 1. A coupling device for mounting an airbag module (14) to be oscillating on a steering wheel structure (12) of a vehicle steering wheel (10), comprising: a mounting member (18) having an axial bottom side (20) relative to a steering wheel axis (A) which in the assembled state of the vehicle steering wheel (10) faces the steering wheel structure (12) as well as an opposite axial top side (22) which in the assembled state of the vehicle steering wheel (10) faces the airbag module (14), a contact face (24) provided on the axial bottom side (20) for a damping element (26) for oscillating coupling of the mounting member (18) to the steering wheel structure (12), as well as a locking element (28) disposed on the top side (22) of the mounting member (18) for locking with the airbag module (14), wherein the locking element (28) is configured so that the airbag module (14) can be coupled to the mounting member (18) by a locking connection substantially in an axially fixed manner or in an axially restrictedly movable manner.
 2. The coupling device according to claim 1, wherein the mounting member (18) is a mounting plate which extends substantially perpendicularly to the steering wheel axis (A) and includes plural locking elements (28).
 3. The coupling device according to claim 1, wherein plural locking elements (28) are provided and a damping element (26) is associated with each locking element (28), wherein the locking elements (28) and the associated damping elements (26) are arranged axially in series.
 4. The coupling device according to claim 1, wherein the axial top side (22) of the mounting member a horn contact (50) or an actuating element (53) for activating a beep is arranged and the locking element (28) is configured so that the airbag module (14) can be coupled to the mounting member (18) by the locking connection in an axially restrictedly movable manner.
 5. The coupling device according to claim 1, wherein the coupling device (16) includes a damping element (26) which contacts the contact face (24) on the axial bottom side (20) of the mounting member (18) and couples the mounting member (18) to the steering wheel structure (12) in an oscillating manner so that the mounting member (18) and the steering wheel structure (12) are movable relative to each other at least transversely to the steering wheel axis (A), wherein the damping element (26) is preassembled on the axial bottom side (20) of the mounting member (28).
 6. The coupling device according to claim 5, wherein the damping element (26) extends through an opening (58) of the mounting member (18).
 7. The coupling device according to claim 6, wherein the damping element (26) comprises an annular vibration-damping material (27) having a radial shoulder, wherein an edge of the opening (58) forms a contact face (24) and acts on the radial shoulder of the vibration-damping material (27).
 8. The coupling device according to claim 7, wherein the radial shoulder is configured as a groove (64) in the vibration-damping material (27), wherein the edge of the mounting member opening (58) at least in portions engages in the groove (64).
 9. A subassembly comprising: a steering wheel structure (12), a coupling device (16) according to claim 7, and a screw (66) for mounting the coupling device (16) on the steering wheel structure (12) which screw extends through the annular vibration-damping material (27), wherein the vibration-damping material (27) with an axial end face is adjacent at least in portions to a screw head (68) of the screw (66) and/or with an opposite axial end face is adjacent at least in portions to the steering wheel structure (12).
 10. A subassembly comprising: a steering wheel structure (12), a coupling device (16) according to claim 1, and a damping element (26) for oscillating coupling of the mounting member (18) to the steering wheel structure (12), wherein the damping element (26) is arranged on the axial bottom side (20) of the mounting member (18) and is preassembled together with the mounting member (18) on the steering wheel structure (12).
 11. A subassembly comprising: a prefabricated airbag module (14) and a coupling device (16) according to claim 1, wherein the prefabricated airbag module (14) includes a module cover (54) including a horn contact (50) as well as another module component (56) including a mating contact (52) axially abutting on the horn contact (50), with the module cover (54) being supported to be axially movable relative to the further module component (56) for activating a beep.
 12. A subassembly comprising a prefabricated airbag module (14) and a coupling device (16) according to claim 4, wherein the prefabricated airbag module (14) includes a mating contact (52) axially abutting on the horn contact (50), with the airbag module (14) being supported to be axially movable relative to the mounting member (18) for activating a beep.
 13. A vehicle steering wheel of an automotive vehicle, comprising a steering wheel structure (12), a prefabricated airbag module (14), a coupling device (16) according to claim 1 and a damping element (26) for oscillating coupling of the mounting member (18) to the steering wheel structure (12), wherein the vehicle steering wheel (10) includes a horn contact (50) as well as a mating contact (52) axially abutting on the horn contact (50), and wherein both the horn contact (50) and the mating contact (52) are formed on components of the vehicle steering wheel (10) that are supported so as to be oscillating.
 14. The vehicle steering wheel according to claim 13, wherein the airbag module (14) is secured to the steering wheel structure (12) exclusively by the locking connection to the coupling device (16).
 15. The vehicle steering wheel according to claim 13, wherein the airbag module (14) is secured to the steering wheel structure (12) by means of the coupling device (16), wherein moreover another connection independent of the coupling device (16) is provided between the airbag module (14) and the steering wheel structure (12). 